Sleuthing With the Enemy - S3-E8
Other mistake: When Piper puts the Belthazor flesh into the Belthazor vanquishing potion, she is the only one that gets "blasted" back even though she is the one standing farthest away from the stove and the potion.
Sleuthing With the Enemy - S3-E8
Other mistake: Cole is supposed to be one of the most powerful demons alive, but a small cut from Piper weakens him to the point where he can't even shimmer or keep up his "Cole" appearance.
Sleuthing With the Enemy - S3-E8
Audio problem: When Phoebe fights with Krell in the mausoleum, the vial containing the Belthazor vanquishing potion is heard smashing, but after Krell is vanquished, Phoebe picks up an unsmashed vial and uses it to stage Cole's escape.
Coyote Piper - S3-E9
Revealing mistake: Prue knocked Piper unconscious in the cat fight (after the Coyote Dance), and asked Justin to carry her to the car. But when he is apparently lifting Piper up from the floor, you see Piper standing up by herself.
Coyote Piper - S3-E9
Other mistake: At the beginning of this episode, Tara and Kierken are arguing and Kierken says that he could always "suck you into your little mixing bottle and start again." Then Tara says that "she has a better idea," and then she stabs herself. The life essence automatically flows out of her but the knife was still in her body. Later, the possessed business man stabs himself in front of Piper and she kneels down to see if he was okay and the essence flew into her, without the knife being removed from his body. At the end, when Leo comes down after Prue stabs the possessed Piper, he kneels over her, but the essence does not flow into him. It only flows into him after he takes the knife out of her body.
Coyote Piper - S3-E9
Revealing mistake: After Phoebe has her premonition in the mausoleum, she wipes away the dust from the crypt to reveal Cole's father's name. Just BEFORE they show her wiping the dust away, you can see the letters in the shot of her leaning against the crypt.
We All Scream for Ice Cream - S3-E10
Visible crew/equipment: When Phoebe gets an IM on the laptop Prue walks over to her, and just as Prue sits down at the table we can see the blue tape mark on the floor, where she had been standing. (00:05:50)
We All Scream for Ice Cream - S3-E10
Continuity mistake: When the girls are saying goodbye to their father, Phoebe hugs him around the neck, then lowers her arms while they talk. When her father says "About anything," her left arm jumps back up to being around his neck, and in the next shot, it's down at the side again. (00:40:20)
We All Scream for Ice Cream - S3-E10
Continuity mistake: When Victor is saying goodbye to Prue, Piper, and Phoebe, Prue has her hands in her jeans pockets, then crossed in front of her, then back in her pockets. (00:40:45)
We All Scream for Ice Cream - S3-E10
Visible crew/equipment: When Prue and Phoebe are trying to pull the girl out of the ice-cream truck, in one brief shot, you can see the wires holding the girl up.
Blinded by the Whitelighter - S3-E11
Visible crew/equipment: After the opening credits, when it cuts to Piper and Leo in the dining room the green tape mark is visible under the table, and the red T-mark and long blue tape mark are also visible on the crew's black floor mat behind Leo. (00:04:45)
Blinded by the Whitelighter - S3-E11
Continuity mistake: When Phoebe is looking in the Book of Shadows for information about Eames, she comes across the Belthazor page, and lays the page down flat. In the following shots, the page moves to her hand, then lying down flat, then to her hand again. (00:19:10)
Wrestling with Demons - S3-E12
Continuity mistake: When Phoebe finds the lost and found spell for Piper, the paper the spell is written on moves relative to the top of Phoebe's keepsake box. (00:10:30)
Wrestling with Demons - S3-E12
Deliberate mistake: When Piper froze the demons (near the wrestling) one of the demons moved when she froze him.
Wrestling with Demons - S3-E12
Continuity mistake: When Rasputin first lay on the couch, he was at the end of it, but two shots later he was suddenly in the middle of the couch.
Continuity mistake: While Dantalian tries to steal the Book of Shadows from the attic Piper and Phoebe surprise her, then when Phoebe kicks Dantalian and she falls we see the stuntwoman's footwear has chunky sole ridges, but when the sisters approach Dantalian her shoes have heels. (00:32:10)
Revealing mistake: When Prue talks about her relationship with Justin near the beginning of the episode, she says that she finds him to be very predictable, lacking in mystery or "savoir-faire." That doesn't make sense, though, as "savoir-faire" means "know-how." She probably meant "je ne sais quoi," that is, "I know not what."
Audio problem: When Evil Prue flings Piper and Phoebe back, you see Piper hit a pillar, but with Phoebe's voice of pain. When we see Phoebe fall behind a structure, we hear Piper's voice of pain.
The Good, the Bad and the Cursed - S3-E14
Continuity mistake: After Cole kills the outlaw with an energy ball, he turns around to face Prue. In the following shot, he's facing the other way and turns around again. (00:39:45)
The Good, the Bad and the Cursed - S3-E14
Continuity mistake: When Cole and Prue are about to shimmer to the other plain to find BO, Cole's face has not been shaved. But when they reach the other plain, his face is cleanshaven.
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.